/Engine/Source/Editor/Cascade/Classes/CascadeParticleSystemComponent.h
Collision Handling...
virtual bool ParticleLineCheck ( [FHitResult](API\Runtime\Engine\Engine\FHitResult) & Hit, [AActor](API\Runtime\Engine\GameFramework\AActor) * SourceActor, const FVector & End, const FVector & Start, const FVector & Extent, const [FCollisionObjectQueryParams](API\Runtime\Engine\FCollisionObjectQueryParams) & )